This game is as simple as it gets. Simply slide blocks up, down, left and right to reveal a path for the highlighted red block to make it through the hole and off the screen. This free version has two modes, Relax and Challenge. The only difference between the two modes are whether or not it records how many moves it took you to finish the level. A good addition to this would be to have a timed mode. This app originally started out with 400 levels but later added 200 more as a thank you and sorry for having bugs in an update. I must say, with this many levels I thought there would be more alike and feel like im playing the same level over and over again but this is not the case. Each level is a challenge. One tip for the harder levels is to move the blocks into a position which makes it harder, only to have the ability to move other blocks out of the way for the win. Overall a good free app that last longer than 15 minutes like most other free versions.